In oil and gas production, it is sometimes beneficial to stimulate a reservoir by pumping in high pressure fluids and particulates, such as sand. In order to do this, one or more tubular sections of a tubular installed in the well may need to be isolated for a period of time and re-opened so the well can be produced.
One means of isolation is a frac plug. A frac plug is a hollow, cylindrical plug which can be installed in the tubular to isolate one or more sections. Current designs generally utilize a sealing ball that is pumped into place against the plug. Seating the sealing ball stops fluid flow through the bore of the frac plug. In addition, a seal may be disposed between the outer diameter of the frac plug and the tubular to prevent flow therebetween. Thus, hydrocarbons from the reservoir cannot flow through the bore of the frac plug and cannot divert around the outside of the frac plug. This isolates the selected portions of the well by preventing fluid flow from the surface to the reservoir and vice versa.
Frac plugs are usually built around a central mandrel. Typically, the central mandrel is then positioned in the wellbore and held in place using upper and lower slips. However, such designs may shift within the tubular section when the sealing ball is installed. Additionally, a portion of the wellbore may be horizontal and it can be difficult to position the sealing ball in the horizontal portion. Further, pumping the sealing ball down the wellbore from the surface can slow the oil and gas production process.
What is needed, therefore, is a frac plug which can seal quickly without the need of secondary components.